CN103168827B - Method for preparing freshness-retaining film through Maillard reaction of collagen and chitosan - Google Patents

Abstract

The invention belongs to the technical field of food freshness-retaining processing and provides a method for preparing a freshness-retaining film through Maillard reaction of collagen and chitosan. The method comprises the following steps of: (1), dissolving the collagen and chitosan in an acid aqueous solution, and carrying out reflux reaction in a round-bottom flask to obtain a Maillard reaction product; and (2), cooling the Maillard reaction product to 20 DEG C to 25 DEG C, adding glycerol to the Maillard reaction product for uniformly stirring, and removing air bubbles by ultrasonically treating for 3 minutes to 8 minutes to obtain the freshness-retaining film. The freshness-retaining film prepared by the method disclosed by the invention is safe, healthy, edible and is capable of forming a film layer on the surface of fish and meat to keep the meat fresh and remarkably prolong the shelf life of the meat and fish after being coated on the fish and meat. Besides, the method is simple to operate, easy to control, strong in operability and suitable for industrial production.

Description

Collagen and chitosan prepare method for fresh-keeping coating film through Maillard reaction

technical field

The invention belongs to the technical field of food fresh-keeping processing, and relates to a method for preparing a fresh-keeping coating film, in particular to a method for preparing a fresh-keeping coating film through Maillard reaction of collagen and chitosan.

Background technique

Meat food is the main source of high-quality protein needed by the human body, and it is an indispensable food in people's daily life. At present, my country's meat consumption mainly includes hot fresh meat, frozen meat and chilled meat. Hot fresh meat has problems such as serious pollution, safety and hygiene; frozen meat is less and less popular with consumers because its flavor and nutrition are greatly affected by freezing and thawing; chilled meat has undergone a process of natural defrosting and maturation, and its texture Soft and elastic, compared with hot fresh meat and frozen meat, chilled meat has the advantages of safety and hygiene, delicious taste, delicate taste and high nutritional value. With the improvement of people's living standards, chilled meat will be welcomed by consumers, which is an inevitable trend in the development of fresh meat in the future. However, chilled meat is rich in fat and protein, which is easily used by microorganisms to cause spoilage, resulting in a short shelf life and becoming the main bottleneck restricting its rapid development.

In recent years, due to the advantages of environmental protection, non-toxicity, low cost, and simple operation, fresh-keeping coatings have developed rapidly. Fresh-keeping coatings are generally made of edible substances as raw materials, with or without adding antibacterial agents, and form a film with a porous network structure through the interaction between different molecules to inhibit material exchange and hinder microbial invasion, thereby preventing food spoilage Deterioration can solve the problem of short shelf life of chilled meat. Researchers have done some useful research, for example: Pan Siyi et al. use konjac powder coating to keep fresh and cool pork (Pan Siyi et al., Food Science, 2004, 25(8): 177-180); Jiang Shaotong et al. Phenol, allicin and natural edible film solution were developed into film-coated preservatives to study the film-preservation of chilled pork, and the best process for prolonging the fresh-keeping period of chilled meat was screened out through orthogonal experiments (Jiang Shaotong et al., Food Science, 2010, 31 (10): 313-316); Yang Shengping used chitosan combined with tea polyphenol coating to keep fresh and cool hairtail (Yang Shengping, Jiangsu Agricultural Journal, 2010, 26 (4): 818-821); Xin Meili et al. Research on the effect of chitosan coating combined with low temperature on crispy grass carp fillets (Xin Meili et al., Science and Technology of Food Industry, 2012, 33(9): 398-401).

A large number of studies have shown that: Maillard reaction products have functional properties such as anti-oxidation, anti-mutagenesis, anti-virus, anti-proliferation, and anti-tumor, especially anti-oxidation activity, and have the potential to replace traditional synthetic antioxidants. Maillard reaction, also known as non-enzymatic browning, mainly occurs between the hydroxyl groups of reducing sugars, aldehydes, and enones and the amino groups of amino acids, peptides, proteins, and any nitrogen-containing compounds. At present, there are more researches on the active ingredients in the Maillard reaction products, the mechanism of antioxidant, and the influencing factors of antioxidant activity. For example: Zhang Yinliang et al. evaluated the antioxidant activity of Maillard reaction products produced by the casein-xylose system (Zhang Yinliang et al., Food Science and Technology, 2012, 37(7): 65-70); Zhang Xi et al. discussed whey Film-forming properties of protein-xylose Maillard reaction products and their membrane-encapsulated inhibitory effect on walnut kernel lipid peroxidation (Zhang Xi et al., Food Science, 2011, 32(5): 58-64); Yu Pengwei et al. discussed the fresh-keeping effect of xylose-glycine Maillard reaction products on pork (Yu Pengwei et al., Food Science, 2012, 33(20): 334-338).

Contents of the invention

The purpose of the present invention is to provide a method for preparing a fresh-keeping coating film through Maillard reaction of collagen and chitosan.

A kind of collagen protein and chitosan of the present invention prepare the method for fresh-keeping coating film by Maillard reaction, it comprises the following steps: (1) collagen protein and chitosan are dissolved in acidic aqueous solution, in round bottom flask Medium reflux reaction to obtain the Maillard reaction product; (2) Cool the above-mentioned Maillard reaction product to 20-25°C, add glycerin and stir evenly, and remove air bubbles by ultrasonication for 3-8 minutes to obtain the fresh-keeping coating film.

According to a further feature of the preparation method of the present invention, in the step (1), the pH of the acidic aqueous solution of dissolving collagen and chitosan is 4.0-6.0.

According to a further feature of the preparation method of the present invention, in the step (1), the concentration of collagen is 0.006-0.02 g/mL.

According to a further feature of the preparation method of the present invention, in the step (1), the concentration of chitosan is 0.006-0.02 g/mL.

According to a further feature of the preparation method of the present invention, in the step (1), the reflux reaction temperature is 80-100°C.

According to a further feature of the preparation method of the present invention, in the step (1), the reflux reaction time is 8-10 hours.

According to a further feature of the preparation method of the present invention, in the step (2), the dosage of glycerol is 6-10mL/100mL.

Another object of the present invention is to provide a fresh-keeping method for fish using the fresh-keeping coating. The method is as follows: the fish meat is dipped in the fresh-keeping coating film, drained, and a layer of fresh-keeping film is formed on the surface of the fish meat.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The collagen and chitosan adopted in the present invention have a unique molecular structure and the effect of cross-linking between huge molecules, and they have excellent film-forming properties; chitosan has antibacterial properties, and carries out Maillard reaction with collagen The obtained product has antioxidant properties; therefore, the Maillard reaction product of collagen and chitosan not only has excellent film-forming properties, but also has antibacterial and anti-oxidative properties, and its application in coating film preservation has great potential .

(2) The fresh-keeping coating film of the present invention is safe, healthy and edible. After it is used as a coating film on fish meat, a thin film can be formed on its surface, which can inhibit the exchange of internal and external gas, water and solute and hinder the invasion of microorganisms. , maintain the freshness of the meat and significantly extend its shelf life.

(3) The present invention is simple in operation, easy to control, strong in operability, and suitable for industrial production.

Detailed ways

The present invention will be further described below through specific examples, but the present invention is not limited to these examples.

The present invention comprehensively evaluates the fresh-keeping effect of the present invention by using volatile basic nitrogen (TVB-N), total bacterial colony (TVC), thiobarbituric acid value (TBA) and pH value as indicators.

Usually, when the volatile basic nitrogen (TVB-N) is less than 20mg/100g, the total bacterial colony (TVC) is less than 10 ⁶ CFU/g, the thiobarbituric acid value (TBA) is less than 2.0mg/kg and the pH is less than 7.0 , fish can be eaten.

Determination of volatile basic nitrogen (TVB-N): according to the method of GB/T 5009.44-2003.

Determination of total bacterial colony (TVC): According to the method of GB 4789.2-2010.

Determination of thiobarbituric acid value (TBA): according to the method in the literature (Rong Jianhua et al., Food Science and Technology, 2012, 37(4): 115-118).

Example 1

(1) Preparation of fresh-keeping coating film: Weigh 0.6g collagen and 2.0g chitosan with a balance and dissolve them in 100mL of pH 6.0 aqueous solution. hours to obtain the Maillard reaction product. Pour the Maillard reaction product into a beaker, cool to room temperature, add 10 mL of glycerin, stir evenly, and ultrasonically remove air bubbles for 3 minutes to obtain a fresh-keeping coating.

(2) Coating: remove the scales and viscera of the fresh tilapia, wash it, slice it, put it in the above-mentioned fresh-keeping coating film for 2 minutes, take it out and drain it for 1 minute, at this time a layer of fresh-keeping film is formed on the surface of the fish fillet .

(3) Refrigeration treatment: Take two high-temperature and high-pressure sterilized petri dishes that have been cooled to room temperature, one large and one small, put the above-mentioned fish fillets coated with the film into the small petri dishes, and then use the large petri dish Cover the small ones and put them together in the refrigerator at 4°C.

(4) Measurement results: The above-mentioned coated fish fillets were refrigerated for 18 days and taken out to measure relevant indicators. The volatile basic nitrogen (TVB-N) was 16.86mg/100g, the total number of colonies (TVC) was 10 ^5.63 CFU/g, and the sulfide The barbituric acid value (TBA) is 0.63mg/kg, and the pH is 6.78. Fish fillets also have high edible value.

Example 2

(1) Preparation of fresh-keeping coating film: Weigh 2.0g collagen and 0.6g chitosan with a balance and dissolve them in 100mL of pH 4.0 aqueous solution. hours to obtain the Maillard reaction product. Pour the Maillard reaction product into a beaker, cool to room temperature, add 6 mL of glycerin, stir evenly, and ultrasonically remove air bubbles for 8 minutes to obtain a fresh-keeping coating.

(2) Coating: remove the scales and viscera of the fresh tilapia, wash it, slice it, put it in the above-mentioned fresh-keeping coating film for 2 minutes, take it out and drain it for 1 minute, at this time a layer of fresh-keeping film is formed on the surface of the fish fillet .

(3) Refrigeration treatment: Take two high-temperature and high-pressure sterilized petri dishes that have been cooled to room temperature, one large and one small, put the above-mentioned fish fillets coated with the film into the small petri dishes, and then use the large petri dish Cover the small ones and put them together in the refrigerator at 4°C.

(4) Measurement results: The above-mentioned coated fish fillets were refrigerated for 16 days and then taken out to measure relevant indicators. The volatile base nitrogen (TVB-N) was 17.28mg/100g, the total bacterial colony (TVC) was 10 ^5.71 CFU/g, and the sulfide The barbituric acid value (TBA) is 0.67mg/kg, the pH is 6.84, and the fish fillet also has a high edible value.

Example 3

(1) Preparation of fresh-keeping coating film: Weigh 1.3g collagen and 1.3g chitosan with a balance and dissolve them in 100mL of pH 5.0 aqueous solution, mix well and then reflux the mixture in a round bottom flask at 90°C hours to obtain the Maillard reaction product. Pour the Maillard reaction product into a beaker, cool to room temperature, add 8 mL of glycerin, stir evenly, and ultrasonically remove air bubbles for 5 minutes to obtain a fresh-keeping coating.

(2) Coating: remove the scales and viscera of the fresh tilapia, wash it, slice it, put it in the above-mentioned fresh-keeping coating film for 2 minutes, take it out and drain it for 1 minute, at this time a layer of fresh-keeping film is formed on the surface of the fish fillet .

(3) Refrigeration treatment: Take two high-temperature and high-pressure sterilized petri dishes that have been cooled to room temperature, one large and one small, put the above-mentioned fish fillets coated with the film into the small petri dishes, and then use the large petri dish Cover the small ones and put them together in the refrigerator at 4°C.

(4) Measurement results: The above-mentioned coated fish fillets were refrigerated for 18 days and taken out to measure relevant indicators. The volatile base nitrogen (TVB-N) was 16.98mg/100g, the total number of colonies (TVC) was 10 ^5.65 CFU/g, and the sulfide The barbituric acid value (TBA) is 0.60mg/kg, the pH is 6.73, and the fish fillet also has a high edible value.

Claims (6)

1. collagen protein and chitosan are prepared a method for fresh-keeping film-coating by Maillard reaction, it is characterized in that comprising the following steps:

(1) collagen protein and chitosan are dissolved in acidic aqueous solution, in round-bottomed flask, 80 ~ 100 ℃ of back flow reaction are 8 ~ 10 hours, obtain maillard reaction product;

(2) above-mentioned maillard reaction product is cooled to 20-25 ℃, adds glycerine to stir, ultrasonic 3-8 minute removes bubble, obtains described fresh-keeping film-coating.

2. preparation method according to claim 1, is characterized in that: in described step (1), the pH of the acidic aqueous solution of described dissolving collagen protein and chitosan is 4.0 ~ 6.0.

3. preparation method according to claim 1, is characterized in that: in described step (1), the concentration of collagen protein is 0.006 ~ 0.02g/mL.

4. preparation method according to claim 1, is characterized in that: in described step (1), the concentration of chitosan is 0.006 ~ 0.02g/mL.

5. preparation method according to claim 1, is characterized in that: in described step (2), glycerine consumption is 6 ~ 10mL/100mL.

6. the fresh-keeping film-coating of the preparation of method, for oppressing fresh-keeping method, is characterized in that according to claim 1: the flesh of fish is put into described fresh-keeping film-coating and flood, drain, on the surface of the flesh of fish, form one deck antistaling film.